Convertible attachment plugs



June 20, 1961 c. J. AARLAHT 2,989,719

CONVERTIBLE ATTACHMENT PLUGS Filed Sept. 11, 1958 ATTORNEY limited Thisinvention relates to electrical fixtures and more particularly to aconvertible plug.

It is an object of the present invention to provide a single universallyadjustable plug that may be used for all types of two and three socketwall receptacles.

Another object of the present invention is to provide a universal plugof the above type having individually adjustable prongs for selectiveengagement with various types of standard wall receptacles in a simpleand eflicient manner.

Other objects of the invention are to provide a convertible plug bearingthe above objects in mind which is of simple construction, has a minimumnumber of parts, is inexpensive to manufacture and eflicient inoperation.

For other objects and for a better understanding of the invention,reference may be had to the following detailed description taken inconjunction with the accompanying drawing, in which:

FIGURES l to 5 are plan views of various kinds of standard wallreceptacles with which the plug made in accordance with the presentinvention may be used;

FIGURE 6 is a side elevational view, with parts broken away, of aconvertible plug made in accordance with the present invention;

FIGURE 7 is a plan view of the exterior base plate of the plug shown inFIGURE 6;

FIGURE 8 is a transverse cross sectional view taken along line 8-8 ofFIGURE 6;

FIGURE 9 is a transverse cross sectional view taken along line 9-9 ofFIGURE 6;

FIGURE 10 is an enlarged fragmentary cross sectional view taken alongline 10-10 of FIGURE 9;

FIGURE 11 is an enlarged transverse cross sectional View taken alongline 1111 of FIGURE 9;

FIGURE 12 is an enlarged transverse cross sectional view taken alongline 12-12 of FIGURE 9; and

FIGURE 13 is an enlarged transverse cross sectional view taken alongline 13-13 of FIGURE 9.

Referring now more in detail to the drawing, a convertible plug 15 madein accordance with the present invention is shown to include a mainhousing within which all of the working parts are disposed. This housingincludes a bell shaped dome 16, a wire terminal plate 17. an outsidebase plate 22, a composite control plate consisting of an outermostplate 18 and innermost plate 20, a cylindrical side wall 28, and spacerpins 26 securing the plates 17 and in assembled relationship. Theconduit 30 having power wires 32 and a ground wire 34 extends into theinterior of the dome 16 and is connected to terminals 31, 33, mountedonthe wire terminal plate 17, in the manner shown in FIG. 6. Theterminals 31 are connected by means of lead wires 36, extending throughinsulated sleeves 38, to the bases of a pair of prongs 42, only one ofwhich is shown in FIG. 6, and both of which are shown in FIG. 8.

As is more clearly shown in FIGURES 7 through 13 of the drawing, thebase 40 of each prong 42 includes a pair of annular flanges 41 and 43arranged in spaced apart relationship on said base with the flange 43,which has a diameter larger than the diameter of the flange 41, adjacentto the end of the base 40 to which the lead wire 36 is connected. Theflange 41 of the base 40 is rotatably supported within an enlargedcounterbore 48 in the innermost plate 20 of the control member, withwhich smaller bores 44, 46 communicate, as is specifically shown in FIG.13. As a result the prongs 42 are rotatable within these bores 44, 46,48, into a predetermined position. The outside closure plate 22 has apair of three sided slots 50, each providing three diiferent positionsof orientation for the prongs 42, so as to be accommodated within anyone of the pairs of the sockets 81, 81a, 81b illustrated in FIGURES l to3 of the drawing. Screws 54 releasably secure the outside plate 22 tothe associated elements, so that it may be removed and the prongs 42rotated into the desired position, following which the plate 22 isplaced with the prongs extending outwardly through the selected ones ofthe slots in the three sided openings 50.

The control plates 18, 20 are also provided with T- shaped slots 60, 56,between which an enlarged T-shaped slot 58 is disposed. At two of thethree corners of the T-shaped slot 56 on the inner member 20, the slotis enlarged to provide enlarged access openings 61 into which thesmaller flange 59 carried by each base of both the ground post 62 andground blade 68 may be slidably received. Ground wires 72, leading fromthe terminal 33, are connected respectively to the bases of the groundpost 62 and the ground blade 68, in the manner shown in FIG. 6. Thelarger flange 66 is maintained in sliding contact with the surface ofthe inside control plate 20 when either the ground post or ground bladeis extended. The outside plate 22 is also provided with a centralopening 64 having diametrically opposite extending slots 70 forselectively receiving the ground blade 68 when moved into alignmenttherewith.

A guide pin 74 is also provided for each base 75 of the ground post andground blade so as to guide such element for selective longitudinalmovement into and out of proper position with the central bore 64 of theoutside plate 22. Compression springs 76 associated with each such guidepin 74 normally urges the ground post or ground blade outwardly towardthe extended position.

In actual use, the plug made in accordance with the present inventioncan be adjusted to he used with any one of the receptacles illustratedin FIGURES 1 to 5 of the drawing. In FIGURE 1, a conventional outlet 80is shown wherein the sockets 81 are in spaced apart parallelrelationship in the absence of any ground socket. As a result, the plug15 is adjusted so as to extend both the ground blade and ground postinto the interior of the housing and the prongs 42 placed in spacedapart parallel relationship. When adjusting the plug for use with thereceptacle 80a illustrated in FIGURE 2 of the drawing, where the sockets81a are contained within a substantially single plane, the plug isadjusted in a similar manner,

except that the prongs 42 are rotated degrees out of I the position usedin connection with the receptacle as shown in FIGURE 1.

In using the plug for the receptacle illustrated in FIG- URE 3, theprongs 42 are rotated to correspond to the sockets 81b and the groundblade 68 is extended into the position of the ground socket 82.

In FIGURE 4, the sockets 81b are in the same position, but the groundsocket 82a of the receptacle 80c requires that the ground blade 68 berotated 90 degrees out of the position used when connected with thereceptacle of FIGURE 3.

Finally, in using the receptacle 802;! shown in FIGURE 5 of the drawing,the prongs 42 are returned to the original spaced apart parallelrelationship, the ground blade 68 is inserted into the interior of thehousing, and the ground post 62 is extended outwardly through thecentral openings of the control plates to be received within the groundsocket 83.

While various changes may be made in the detail construction, it shallbe understood that such changes shall be within the spirit and scope ofthe present invention as defined by the appended claim.

What I claim as new and desire to protect by Letters Patent of theUnited States is:

A convertible plug comprising, in combination, a housing having aterminal wire plate at one end, a composite control plate assembly atthe opposite end, said control plate assembly including an outermostplate and an innermost plate arranged face to face with the outermostplate, spacer pins securing the terminal wire plate in assemblyrelationship with the innermost plate of said control plate assembly, aplurality of bores formed in said control plate assembly, a pair ofprongs, means supporting said prongs in the bores of said control plateassembly for relative rotation about individual longitudinal axeswhereby said prongs are adapted to be arranged in predetermined angularpositions with respect to each other, said prongs being electricallyconnected to terminals on said terminal wire plate, an outside baseplate arranged face to face with the outermost plate of said controlplate assembly, a plurality of angularly arranged openings in saidoutside base plate through which said prongs project and are therebyretained in predetermined adjusted positions, and means connecting saidoutside base plate with the outermost plate of said control plateassembly whereby said outside base plate is detachable from said controlplate so that said prongs can be rotated in the control plate assemblyfrom one adjusted position to another adjusted position when the outsidebase plate is removed from the plug.

References Cited in the file of this patent UNITED STATES PATENTS

